The creation of male sterile plants is of economic interest in the production of hybrid seeds. Male sterility prevents self-pollination which otherwise occurs in many plant species and hinders breeding and hybrid seed production.
Transcription of many plant genes is controlled in a temporal and spatial manner. Regulation of gene activity is mediated by the interaction of trans acting factors and cis regulatory elements in the promoter region of a gene.
Of particular interest are genes which are expressed primarily or exclusively in the sexual tissue of the plant, such as anther or pollen tissue. Such genes can be used to express polypeptides that are not naturally produced in the anther or pollen. For example, the promoter region from an anther specific gene may be used to express a polypeptide which will disrupt formation of viable pollen when expressed in the anther cells, resulting in a male sterile plant
European Patent Application 0 420 819 A1 describes the use of the wunl gene to produce male sterile plants.
U.S. Pat. No. 5,086,169 describes the isolation of the promoter region from the Zm13 clone of a pollen-specific gene of corn, and its use to express genes in pollen.
PCT WO 89/10396 describes the use of male-sterility DNAs and anther-specific cDNAs TA13, TA26 and TA29. The developmental expression profiles of TA13 and TA29 matched two cDNA clones isolated by the applicants, ANT5 and ANT45, respectively.
PCT WO 90/08825 describes three gene sequences, pMS10, pMS14 and pMS18, and their use in recombinant DNA sequences with the GUS reporter gene GUS. No evidence of expression is given.
PCT WO 90/08831 describes a disrupter gene known as the mammalian uncoupling protein (UCP) gene which inhibits respiration in cells.
PCT WO 90/08828 describes molecular methods of hybrid seed production in which recombinant DNA molecules using pollen specific promoters are used to control the production of fertile pollen in plants.